package com.john.design.七大原则.单一职责原则;

/**
 * @Author: JohnCoding
 * @Description:
 * @date: 2020/8/9 21:44
 */
public class JavaCourse implements ICourse{

    public String getCourseName() {
        return null;
    }

    public byte[] getCourseVideo() {
        return new byte[0];
    }

    public void refoundCourse() {

    }

    public void buyCourse() {

    }
}
